Production of artificial filaments, threads, and the like



Jan. 15, 1957 H. EDWARDS ET L PRODUCTION OF ARTIFICIAL FILAMENTS, THREADS, AND T Filed May 15, 1954 HE LIKE 1 (l'laim. (Cl. 10t:165)

section or" the filaments under specific conditions with selected dyestuffs. In addition to the difference in dyeing afiiuity and in swelling property between the skin and core,

- the cellulose molecules of the skin are believed to be more highly orientated than those of the core.

The object of the present invention is to obtain modified viscose filaments which have a skin substantially thicker 7 than is normally obtained.

According to the present invention a process for the production of artificial filaments comprises extruding viscose containing at least 0.1 millimole cose of a diaryl thiourea having the general formula where R1 and R3 are hydrogen or aliphatic or aryl radicals and R2 and R4 are aryl radicals, into an aqueous coagulating bath containing sulphuric acid, sodium sulphate and zinc sulphate.

The preferred minimum concentration for addition to the viscose is one millimole per 100 grams of.

maximum concentration is 10 millimoles per 100 grams of viscose. a skin substantially thicker thiourea necessary to give a desired cross-sectional shape and a surface free from crenulations. The coagulating bath preferably contains from /2 to 15 percent of zinc sulphate.

The present invention also includes viscose containing at least 0.1 millimole per 100 grams of the viscose of a diaryl thiourea having The general formula wherein R1 and R3 are hydrogen or aliphatic or radicals and R2 and R4 are aryl radicals.

aryl 7 Patented Jan. 15, 1957 The preferred diaryl thiourea for present invention is thiocarbanilide In addition to the stantial increase in skin thickness the filaments obtained by the use according to the Example Viscose containing 7.4 percent of cellulose, 7.0 percent of caustic soda and 1.1 percent of combined sulphur was prepared in the usual manner. 1.0 millimole per 100 grams of viscose of thiocarbanilide was added and the viscose was mixed for one hour. When the viscose was 48 hours old from the beginning of the mixing stage and had a salt figure of 5.7 it was ready for spinning.

through a jet having 750 holes, each 0.003 inch in diameter, into an aqueous coagulating bath containing 9.5 percent of sulphuric acid, 20 percent of sodium sulphate and 4.5 percent of zinc sulphate to give a thread of 1550 denier and 750 filaments. The length of immersion in the bath was 24 inches and the temperature of the bath was 48 C. The thread was drawn from the bath at a rate of 28 metres per minute by a godet and then passed through a dilute sulphuric acid bath maintained at a temperature of C. to a second godet rotating at a higher speed than the first godet, to impart an 80 percent stretch to the thread. The thread was collected in a centrifugal spinning box rotating at 4000 revolutions per minute. The cake obtained was washed free from acid, a suitable finish was applied and the cake was dried.

The filaments had a non-crenulated surface and the filaments were bean shaped in cross-section. The amount of skin was at least 50 percent greater than the amount What we claim is:

Viscose containing at least 0.1 millimole per grams of the viscose of thiocarbanilide.

References Cited in the file of this patent UNITED STATES PATENTS 2,118,293 Brinker May 24, 1938 2,322,981 Ubbelohde June 29, 1943 2,435,295 Stasse Feb. 3, 1948 

